No problem, here you go. It's function is to break the draft if it increases beyond the desired point by allowing room air to be pulled up the chimney instead of through your firebox. This keeps from over firing the unit and saves your fuel to heat your home instead of the outdoors. Most of us use the RC but Field Controls actually recommends the M for coal. It doesn't matter too much which one you get but you must have one.

Ok I have come up with my own shaker grate set up. im picking up a 100 gallon propane tank and turn it into the hot water holding tank, i have the domestick hot water coil now and all the metal. Im going to try and start this thing with alot of picks.I need to start with the tank first.then the stove .thanks for all the help

As far as the grates go, if you are to make your own, you can either have them run front to back, or side to side, both utilizing a roller system. In my drawing the grates run side to side and use a round rod that each grate is connected to that shakes all of them via one handle, I will draw it another day to get into more detail. Or you can split them up and have two handles, one for operating the front half, and one for operating the back half. Hope this helps.